A common practice during the production of fiber products is to collect and wind strands of filaments onto a carrier to produce a fiber bundle that may be referred to as a ball, winding, package, cake or doff. These fiber bundles are then used to store, transport and supply fiber linearly into processes such as roving, rewinding, braiding, twisting, weaving, plying, knitting, chopping, pultrusion, filament winding, prepregging, wire coating or cabling for the production of products such as chopped strand mat, yarn wound onto bobbins, multi-end rovings or fabrics or other materials. Typically, a number of these fiber bundles are arranged in a creel or other assembly with individual fibers then being drawn from the separate bundles and passed either singly or in combination into one or more subsequent processes.
In many instances, it is helpful to adjust the tension of the fiber as it exits the feed tube to within a desired range, both to control the tension entering any subsequent processing and to provide a generally uniform tension for a plurality of fibers exiting various feed tubes. Winding operations in particular benefit from the use of a tensioning device between the feed tube and the winder to maintain an even tension in the fiber. Although a variety of tensioner designs are available, a spring tensioner capable of applying a uniform tension as the fiber passes at high speed and does not damage the strand even at high tension levels is preferred. Depending on the application, however, other types of tensioners, including post and disc, breaker bars/alligator clips, electromagnetic breaking/tensioning devices and ball-in-tube tensioners, could also be used in conjunction with the basic feed assembly to perform the desired tensioning.
As will be appreciated, the rate at which the final product may be produced is limited, at least in part, by the rate at which the fiber can be drawn from the creel and supplied to the desired manufacturing operation in a safe and sustainable manner. Prior art techniques that have been employed to control and guide the fiber as it is withdrawn from the creel include ring-shaped guides, eyelets and rollers manufactured from various ceramic and metallic materials. Guides fashioned from metals, such as steel, that are subject to corrosion are frequently coated with a layer of polished nickel or chrome to reduce or prevent corrosion of the guide surface and reduce the damage to the fiber as it is drawn through or across the guide. For instance, U.S. Pat. No. 5,273,614 to Grimshaw et al. discloses a particular construction for redirect rollers for guiding spaced tows. U.S. Pat. No. 4,944,077 to Bollen provides a method of reducing the air friction of yarns drawn from a bobbin at high speed in which a region of accelerated air surrounds the yarn. U.S. Pat. No. 6,182,475 to Lee provides yet another yarn guiding device for feeding yarn from a creel to a knitting needle utilizing a yarn guiding assembly constructed from a combination of zirconium oxide and yttrium oxide. Other work has been directed to modifying the creel itself. For example U.S. Pat. No. 5,639,036 to Flamm provides a textile machine in which the creel is pivotably supported on a pivot shaft with the motion of the shaft and the creel being controlled with an electric motor and a transmission belt unit.
It has been the inventors' experience, however, that those systems that include open frame assemblies remain susceptible to wrapping and binding of the fiber as the fiber feed speed increases. When the terminal operation is capable of accepting and using fiber at higher rates, the reduced fiber feed speed directly limits the productivity of the entire operation. Similarly, downtime resulting from fiber breaks and risk to operators presented by flailing ends of broken fibers further compromise efficiency and safety of the operation. The present invention was developed in order to address these limitations and safety issues and thereby allow improved high-speed operation of fiber feed operations.